The average base price of a 500g tub of Ben & Jerry's ice cream has risen from £3.99 to £4.18 over the past month across the big four, BrandView.co.uk data shows.
Ben & Jerry's owner Unilever said the hike was forced by increased commodity costs, with sugar prices having this week hit a 30-year high.
"We have worked hard to take on as many of these costs as possible through being more efficient but had to pass limited costs on to our fans," said Pete Harbour, category director for ice cream at Unilever.
The increase hit shoppers as the BRC said food prices were up 4.4% on last year and climbing at their fastest for over a year.
But rivals of Ben & Jerry's welcomed the increase, claiming the £3.99 price barrier previously set by Unilever prevented other premium ice cream tubs going higher.
"People have been getting Champagne at lemonade prices in premium tubs so we completely welcome the price increase," said the boss of one premium ice cream supplier. "Unilever could afford to sell below cost, making everyone else look too expensive, so it is great that this price ceiling has been broken."
Fredericks Dairies, which makes Cadbury ice creams, has in the past accused Ben & Jerry's of "completely de-valuing" the ice cream category through deep discounting and said the price hike was a positive move.
"By breaking the psychological £4 barrier, Ben & Jerry's is helping other ice cream companies pass on essential cost hikes," said founder Frank Frederick.
An insider at one major ice cream brand said Unilever had come under pressure from lower-priced lookalike supermarket own-label tubs introduced this year, as well as Nestlé's range of Potz tubs [rsp: £1.29 for a 220ml tub]. "There's certainly more lower-priced competition now, which might have prompted Unilever to up its prices to flag up its quality," he said.
Niche ice cream makers would also welcome further price hikes, claimed Rufus Carter, MD of The Patchwork Traditional Food Company, which this week clinched a distribution deal with ice cream specialist Stratford Fine Foods for a range of alcohol-infused tubs.
"The unnecessary price-ceiling of £3.99 that crept in over the years is as unwanted as the funny after-taste so many ice creams leave behind," said Carter. "The independent retailers we are targeting say they can't get consumers excited about Ben & Jerry's or Häagen-Dazs anymore."